Should you offer free returns?

In fashion, effectively yes — the conversion gain usually exceeds the return cost. In most other categories, no: paid returns filter out casual ordering without costing many real sales.

What decides it

Whatever the policy is, it has to be visible before checkout. A generous policy discovered after purchase buys nothing, and a restrictive one discovered after purchase costs a customer and a review.

The part that gets skipped

Most support questions are the same five, and answering them before they are asked is cheaper than answering them after.

Unclear delivery timing causes more abandoned carts than price.

Delivery is what a customer remembers, and it is the part most stores control least.

Where an app fits

An app makes the after-sale part easier: order status, reordering and support in the place the customer already has open.